1. In collaboration with Drs. Morell and Friedman of the SHG, our audiology unit has used a battery of tests of central auditory and speech processing in a large cohort of monozygotic and dizygotic twins in order to test the hypothesis that one or more measurable parameters of these phenomena are heritable and, therefore, amenable to molecular genetic approaches to identify the genes underlying variation of these phenotypes. 2. In collaboration with Dr. Drayna of the Laboratory of Molecular Genetics, our audiology unit is using a battery of audiologic tests t detect auditory physiologic abnormalities associated with tune deafness. 3. In collaboration with Drs. Hallett and Garvey of the NINDS, the audiology unit has been involved in the design, implementation, and data analysis for two different safety studies on the auditory system (and hearing) after exposure to transcranial magnetic stimulation (TMS) in adults and children, respectively. TMS is a widely utilized clinical neurophysiologic technique whose effects on hearing have not been adequately characterized for many of the devices, or for children. 4. The Hearing Section continues to be actively involved in the auditory phenotypic assessment of individuals with hearing loss and enlarged vestibular aqueducts (EVA), as well as their siblings and parents. Nearly 80 probands and their families have now been ascertained, and the audiologic data reveals a correlation of the auditory phenotype with the underlying SLC26A4 (PDS) genotype. 5. In collaboration with investigators from other NIH institutes, we continue to evaluate hearing and balance manifestations in Von Hippel-Landau disease (Dr. Linehan, NCI), Turner syndrome (Dr. Bondy, NICHD), Fanconi anemia and other inherited bone marrow failure syndromes (Dr. Alter), neonatal onset multi-system inflammatory disorder (Dr. Goldbach-Mansky, NIAMS), Fabry disease (Dr. Schiffman, NINDS), and Pallister-Hall syndrome (Dr. Biesecker, NHGRI), Smith-Magenis syndrome (Ms. Smith, NHGRI), and Usher syndrome (Dr. Sieving, NEI).